Belt Misalignment Sensing and Sensor Status Sensing Apparatus And Method of Use

Abstract

A misaligned belt sensing apparatus determines when a conveyor belt becomes misaligned, indicating repair or replacement are required. At least one sensing apparatus is placed nearly in contact with the belt which produces heat due to friction between the belt and the apparatus when it comes in contact with same due to misalignment. The sensed temperature is compared to threshold values and indicates when the conveyor belt has become misaligned, as well as determining operational wear status of the sensing apparatus after a number of such misalignments. Each heat sensing apparatus comprises at least one thermally conductive plate where a moving misaligned belt rubs against the thermally conductive plate and generates heat due to friction between the moving belt and the thermally conductive plate, where each plate has one or more independent temperature sensing elements for misalignment detection and indication, also detecting wear status of the plates of the apparatus.

Description

I. BACKGROUND OF THE INVENTION[0001]The use of thermally conductive plates with embedded temperature sensing devices is well known as an apparatus for detecting misalignment of any moving belt such as a conveyor belt and transmitting an electrical signal or other indication to a remote location, to allow the misalignment to be corrected or the conveyor shut down before the heat buildup of the conveyor belt or parts of the machine against which the misaligned belt may rub reaches a dangerous level. These detection devices are often referred to as rub blocks. The action of the belt rubbing against the rub blocks also causes wear of their thermally conductive plates. If such wear goes undetected, the belt can rub completely through one or both plates, rendering the apparatus inoperative or it could cause the temperature sensing element of the rub blocks to fail, again rendering the apparatus inoperative, and further or continued misalignment of the conveyor belt could go undetected.[00...

AI Technical Summary

Benefits of technology

The invention is a device that senses when a conveyor belt is misaligned or when a thermally conductive plate is failing. It uses two thermally conductive plates that get hot when the belt rubs against them. These plates have temperature sensors that can detect the misalignment or wear of the device.

Problems solved by technology

The action of the belt rubbing against the rub blocks also causes wear of their thermally conductive plates.

If such wear goes undetected, the belt can rub completely through one or both plates, rendering the apparatus inoperative or it could cause the temperature sensing element of the rub blocks to fail, again rendering the apparatus inoperative, and further or continued misalignment of the conveyor belt could go undetected.

In environments where the apparatus is mounted on an enclosed conveyor or belt or bucket elevator or similar machines, it is not possible to make a visual inspection of the apparatus without removing it from the machine casing.

No matter how frequent such inspections may be, they are not continuous and therefore it is likely that an undesirable condition will be undetected for some time.

These inspections would normally necessitate frequent machine shutdown for safety reasons and are costly and frequently omitted.

In this way, the theory is that the apparatus which protrudes the most would become worn first and subsequent rubbing on the second apparatus would indicate that the first apparatus has worn excessively and needs replacement.

However this arrangement is not normal practice due to the additional cost of installation of the additional apparatus, the cost of the additional apparatus, the additional space needed for the additional apparatus, and the fact that wear at the location of the additional apparatus is not the same wear at the location of the initial apparatus even when the apparatuses are placed within close proximity to each other.

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